There is a widespread awareness of the need to exercise the human body rhythmically, for long enough periods of time, frequently, and strenuously enough to increase respiration and pulse rate so that the cardiovascular and respiratory systems are stimulated, toned, strenghthened and kept active and healthy. Iso-kinetic exercise which also tones and strengthens the peripheral muscle systems, subjects joints to many repeated movements, and structurally loads skeletal bones to keep them elastic and chemically stimulated so they do not deteriorate because of lack of demand, is ideal for these purposes.
Swimming, cycling, calisthenics and jogging are the most widespread forms of iso-kinetic activity. All exercise the cardiovascular system. Each, however, has limitations. In swimming, the midrif is not fully exercised because twisting and bending are minimized. Since we swim suspended in water, essentially free of gravity, bone structures are not stressed and tendons are not conditioned to withstand sudden strains. Cycling has the same limitations, and the additional limitation of almost no upper body exercise. Well designed calisthenic routines, such as aerobic dance if done non-stop and for sufficient time can work out the entire body very effectively. However, since they are not done against resistance, they do not increase strength to the extent that may be desirable. Jogging is simply a calisthenic essentially challenging the legs alone. It has the dangerous limitation of putting jarring strains on the foot, ankle, knee and hip structures.
There are stationary bikes in widespread use. There are good treadmills which permit very natural running. There are many other kinds of exercising equipment available using weights, springs, motors, clutches, etc., for resistance exercising, but these do not encourage continuous, prolonged, repititious, rhythmic movements of the aerobic, iso-kinetic, cardiovascular respiratory system conditioning kind.
There have been many machines or arrangements of pulleys by which arms and legs have been linked to pull against one another. Clease, U.S. Pat. No. 821,783 is an early example, and Gehri, No. 2,716,027, Fundom, No. 2,772,881, Macabet, No. 3,752,474, Codina, No. 3,979,114, Kupperman, No. 3,999,752, Flannery, No. 4,084,815, and Hayes, No. 4,248,420, others. In all of these patented devices, the pull exerted by one member is transmitted to only one other member, or as in Hayes and Macabet, to two tied members. None provides coordinated resistance of each individual member, with natural movement in opposite directions of each left and each right pair.
The machine of this invention can maximally load the cardiovascular and repiratory systems by providing interconnected coordinated movement of all four limbs at the same time, each providing resistance against which they all move individually. It permits many repititions, continuously and rhythmically, including bending, stretching, twisting, balance and coordination of movements.
One of the objects of this invention is to provide a machine by which one can exercise the body iso-kinetically with self imposed resistance, increasing as the body strenghthens.
Another object is to provide such a machine which is simple, rugged, dependable, and economical.
Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.